1. Field of the Invention
The field of the invention is lightweight flexible pipe catenary systems for deep sea installations.
2. Description of the Related Art
U. S. Pat. No. 6,491,779B1 discloses a flexible pipe made of lightweight composite materials for subsea use. Prior to the invention of said U.S. Pat. No. 6,491,779B1, it was generally known that relatively heavy pipe, usually steel, for subsea use formed a catenary when disposed in seawater from a vessel on the water's surface to the seabed. Such prior systems require the users to provide expensive equipment at the surface or elsewhere to offset the large weight of the steel pipe. In spite of the cost of supporting the weight of the pipe in seawater in the past, the industry has continued to use such heavy pipe with the problems resulting from the weight of the pipe.
Also, prior art flexible non-metallic hoses for use in water depths which are greater than about one-thousand feet could not have been used in this invention, because they would have collapsed to a closed inoperative condition by the seawater pressure at those depths.